Need Advice with Mobo/Cpu/Gpu/Ram

[OLD_HANDS]

Looking for advice on my new build after 5 years, I am unable to decide whether should I go with Ivy bridge or SB-E.

I usually build the PC and keep it for several years so future proofing is important for me.
I frequently upgrade my laptops so the PC serves as backup for tasks which require more heavy lifting.


Approximate Purchase Date: before May 10, 2012
Budget: $1500 - $2000

Overclocking: Yes (will do "easier" overclock on air)
Preferred Website for Parts: would like to avoid newegg to save on taxes.


System Usage from Most to Least Important:
web browsing + MS office
watching movies
Unix+Linux (bsd/fedora) in virtual PC and development (c++/java/perl)
home video editing (large files ~20gb) - Adobe Premiere
video transcoding
Skype video call is always running in background for work or personal
Casual gaming - World of Warcraft


BUILD:

Asus P8Z77-V Deluxe or Pro
Intel Core i7 3770K
Gskill 32gb (4x8gb)
XFX Radeon Double D 7850

OR

Asus P9X79-V Deluxe or Pro
Intel Core i7 3930K
Gskill 64gb (8x8gb)
XFX Double D 6950 x 2 (crossfire)


my reason for choosing XFX Double D is better cooling and two DVI ports as I would like to use old monitors.


Parts not required: (hoping to reuse as I already have these)
- Corsair - 620HX
- Antec P180 (back I/O ports might not match with cutout)
- Mushkin Chronos DX 240gb (new)
- Windows 7 Pro (new)
- Samsung Syncmaster 24" (1600x1200)
- Dell Ultrasharp 19"
- keyboard/mouse/hdd's/OD


Thanks very much for your help.

 

[OLD_HANDS]

choices choices choices!

I believe I would only need about max 9gb of ram i.e 3gb x 2 for each virtual PC + 3gb for the OS for daily use.

Would the additional ram help during video editing and transcoding, also is there any downside to using maximum ram supported by motherboard?

If the additional ram does not help then I will buy only 16gb and save some money

Also would two AMD 6870 in crossfire be better than single AMD 7850 for video editing?

Currently 6870 is on SALE so I can buy two and crossfire them with only additional $30 hit